Emission Control Systems

Abstract

A separation column ( 12 ) for an emission control system, the column including: an exhaust gas inlet ( 41 ) for receiving polluted exhaust gases therethrough; a first packed bed ( 37 ) at a predetermined first level above said exhaust gas inlet; first liquid distribution means ( 39 ) above said first packed bed for distributing liquid onto said first packed bed; a second packed bed ( 38 ) at a predetermined second level below said exhaust gas inlet; second liquid distribution ( 40 ) means below said first packed bed and above said second packed bed for distributing liquid onto said second packed bed; cooling means ( 46 ) between said second liquid distribution means and said second packed bed for cooling liquid from said second distribution means and entrained exhaust gases; an exhaust gas outlet ( 35 ) above said first packed bed for discharging cleaned exhaust gases therethrough; and a contaminated liquid outlet ( 36 ) below said second packed bed.

1 . A separation column for an emission control system, the column including: an exhaust gas inlet for receiving polluted exhaust gases therethrough; a first packed bed at a predetermined first level above said exhaust gas inlet; first liquid distribution means above said first packed bed for distributing liquid onto said first packed bed; a second packed bed at a predetermined second level below said exhaust gas inlet; second liquid distribution means below said first packed bed and above said second packed bed for distributing liquid onto said second packed bed; cooling means between said second liquid distribution means and said second packed bed for cooling liquid from said second distribution means and entrained exhaust gases; an exhaust gas outlet above said first packed bed for discharging cleaned exhaust gases therethrough; and a contaminated liquid outlet below said second packed bed. 
   
   
       2 . A separation column for an emission control system, including: an exhaust gas inlet for receiving polluted exhaust gases therethrough; a first packed bed at a predetermined first level above said exhaust gas inlet; first liquid distribution means above said first packed bed for distributing liquid onto said first packed bed; a second packed bed at a predetermined second level below said exhaust gas inlet; second liquid distribution means below said first packed bed and above said second packed bed for distributing liquid onto said second packed bed; cooling means between said exhaust gas inlet and said second packed bed for cooling exhaust gases entering said column through said exhaust gas inlet; an exhaust gas outlet above said first packed bed for discharging cleaned exhaust gases therethrough; and a contaminated liquid outlet below said second packed bed. 
   
   
       3 . A separation column according to  claim 1 , wherein said exhaust gas inlet is arranged to direct exhaust gases onto said cooling means. 
   
   
       4 . A separation column according to  claim 1 , wherein said first and second packed beds are packed with expanded metal foil. 
   
   
       5 . An emission control system, including: a separation column, an exhaust gas inlet for receiving polluted exhaust gases therethrough; a first packed bed at a predetermined first level above said exhaust gas inlet; first liquid distribution means above said first packed bed for distributing liquid onto said first packed bed; a second packed bed at a predetermined second level below said exhaust gas inlet; second liquid distribution means below said first packed bed and above said second packed bed for distributing liquid onto said second packed bed; cooling means between said second liquid distribution means and said second packed bed for cooling liquid from said second distribution means and entrained exhaust gases; an exhaust gas outlet above said first packed bed for discharging cleaned exhaust gases therethrough; a contaminated liquid outlet below said second packed bed; a pre-cooler having a cooling chamber with a hot exhaust gas inlet for receiving polluted exhaust gases therethrough and an exhaust gas outlet in fluid communication with the exhaust gas inlet of said separation column, and cooling means for cooling hot exhaust gases as they flow through said cooling chamber. 
   
   
       6 . An emission control system, including: a pre-cooler having a cooling chamber with a hot exhaust gas inlet for receiving polluted hot exhaust gases therethrough and an exhaust gas outlet; cooling means for cooling hot exhaust gases as they flow through said cooling chamber; and a separation column including; an exhaust gas inlet in fluid communication with the exhaust gas outlet of said separation column for receiving polluted exhaust gases therethrough; a first packed bed at a predetermined first level above said exhaust gas inlet; first liquid distribution means above said first packed bed for distributing liquid onto said first packed bed; a second packed bed at a predetermined second level below said exhaust gas inlet; second liquid distribution means below said first packed bed and above said second packed bed for distributing liquid onto said second packed bed; cooling means between said exhaust gas inlet and said second packed bed for cooling exhaust gases and liquid vapor entering said column through said exhaust gas inlet; an exhaust gas outlet above said first packed bed for discharging cleaned exhaust gases therethrough; and a contaminated liquid outlet. 
   
   
       7 . An emission control system according to  claim 5 , including a mixer for mixing liquid with the polluted exhaust gases prior to entry to said separation column. 
   
   
       8 . An emission control system according to  claim 7 , wherein said mixer is arranged to mix liquid with the polluted exhaust gases downstream of said cooling chamber. 
   
   
       9 . A method of controlling the emission of pollutants, including: providing a separation column having an exhaust gas inlet for receiving polluted exhaust gases therethrough; a first packed bed at a predetermined first level above said exhaust gas inlet; first liquid distribution means above said first packed bed for distributing liquid onto said first packed bed; a second packed bed at a predetermined second level below said exhaust gas inlet; second liquid distribution means below said first packed bed and above said second packed bed for distributing liquid onto said second packed bed; cooling means between said second liquid distribution means and said second packed bed for cooling liquid from said second distribution means and entrained exhaust gases; an exhaust gas outlet above said first packed bed for discharging cleaned exhaust gases therethrough; and a contaminated liquid outlet below said second packed bed; cooling hot exhaust gases to a predetermined temperature; introducing the cooled exhaust gases into said separation column through its exhaust gas inlet; and distributing liquid onto the first and second packed beds in the separation column. 
   
   
       10 . A method according to  claim 9 , including maintaining the cooling means at a temperature of less than about 5 degrees Celsius. 
   
   
       11 . A method according to  claim 9 , including maintaining the cooling means at a temperature of less than about 2 degrees Celsius. 
   
   
       12 . A method according to  claim 9 , including mixing liquid with the exhaust gases prior to introduction to the separation chamber. 
   
   
       13 . A method according to  claim 12 , wherein the liquid is mixed with the exhaust gases after they have been cooled to said predetermined temperature. 
   
   
       14 . A method according to  claim 9 , wherein the cooling chamber of the pre-cooler is cooled by application of liquid onto the housing defining the chamber. 
   
   
       15 . A method according to  claim 9 , wherein said predetermined temperature results in the temperature of gases above said first liquid distribution means being between about 2 degrees Celsius and about 190 degrees Celsius. 
   
   
       16 . A method according to  claim 9 , wherein said pre-cooler and said separation column are selected for specified exhaust gas characteristics which result in the temperature in the separation column above the first packed bed being between about 2 degrees Celsius and about 190 degrees Celsius. 
   
   
       17 . A method according to  claim 9 , wherein said pre-cooler and said separation column are selected for specified exhaust gas characteristics which result in the temperature in the separation column above the first packed bed being between about 2 degrees Celsius and about 40 degrees Celsius. 
   
   
       18 . A method according to  claim 9 , wherein liquid being distributed by the first and second liquid distribution means is less than about degrees Celsius. 
   
   
       19 . A method according to  claim 9 , wherein liquid being distributed by the first and second liquid distribution means is less than about 2 degrees Celsius. 
   
   
       20 . A method according to  claim 9 , wherein liquid being mixed with the hot exhaust gases is less than about 5 degrees Celsius. 
   
   
       21 . A separation column for an emission control system, the column including: an exhaust gas inlet for receiving polluted exhaust gases therethrough; a first packed bed at a predetermined first level above said exhaust gas inlet; first liquid distribution means above said first packed bed for distributing liquid onto said first packed bed; a second packed bed at a predetermined second level below said exhaust gas inlet; second liquid distribution means below said first packed bed and above said second packed bed for distributing liquid onto said second packed bed; and an exhaust gas outlet above said first packed bed for discharging cleaned exhaust gases therethrough. 
   
   
       22 . A method of controlling the emission of pollutants according to  claim 9  wherein the liquid is water or water which contains additives. 
   
   
       23 . A method of controlling the emission of pollutants according to any of the preceding claims wherein the liquid is water which contains additives. 
   
   
       24 . A separation column as hereinbefore described with reference to the accompanying drawings. 
   
   
       25 . An emission control system as hereinbefore described with reference to the accompanying drawings. 
   
   
       26 . A method of controlling the emission of pollutants as hereinbefore described with reference to the accompanying drawings.